Process for making x-ray anodes



E. G. GILSON PROCESS FOR MAKING X-RAY ANODES Filed June 15, 1927 Inventor: v Emery 6.6ilson,

Has Attorney.

Patented May-29,1928.

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PROCESS FOR MAKING X-BAY .ANODES.

Application filed July 15.1927, Serial No. 206,102.

The present invention relates to the manufaeture of electrodes and more particularly to the manufacture of tungsten anodes .for

X-ray tubes. Heretofore, in the mannfae- 10 temperature of about .1400 C. The bar is then reheated by an electric current, swaged into the desired shape, ground and swagedto a stem of molybdenum or other suitable material.

15 It is one of the objects of the present invention to provide an improved process'for ac ratus shown in Fig. 1; while Fig. 3 is a perspective view of an X-ray anode constructed in accordance with the present process. Referring to the drawings, I have indicated at 1 the base plate of a press. A stationary angular metal member 2 is bolted to the base plate while a movable metal memher 3 is mounted on plate 1 opposite member'- 2. A pair of flat, water coo ed copper conductors 4 and 5 are mounted adjacent plates 2 and 3 respectively, and spaced therefrom *by insulators Sand 7. An insulator 8 is inserted between plate 1 and the lower ends of member 3 and conductor 4, and a similar insulator 9 is inserted between plate 1 and the lower ends of conductor 5 and insulator 7. A pair of carbon blocks 10 and 11,secured in any suitable manner to conductors 4 and 5, are adapted to supply current to a carbon mold 12 and to firmly clamp the mold in position on the press. Mold 12 is substantially rectangular in cross section and is provided with'a circular opening 13 extending therethrough' in which slidable carbon members 14 and 15 are mounted. The lower member 15 is-provided with a central opening 16 per end of the carbon member 15 and proe'ct a desired distance above that member.

cation of heat and. pressure to the powdered adapted to register with an opening 17 in the base plate '1, while the upper member 14 has an inclined face portion of substantially. the same form as the face portion of the finished anode. A stem 18, which may be made from molybdenum or tungsten, extends through the openings 16 and 17, and is provided at its upper end with an enlarged por-- tion so that the stem may rest upon the up- In operation, the carbon member 15 is placed on the press so that its opening 16 registers with the opening 17 in the plate 1. Mold 12 is then placed over the'movable member 15 and the block 10 moved into contact with the mold 12 by suitable pressure means applied tothe movable plate 3. A refractory powder, suchas tuhgsten, is then placed in the opening 13' in the mold 12 so as to completely surround and extend above the upper end of the rod 18. The movable carbon member 14 is then inserted in mold 12 and a pressure of about 1000 pounds per square inch or more applied thereto by a plunger 19. Simultaneous with the application of pressure, current is supplied to the mold and powdered refractory material through copper conductors 4 and 5 and carbon blocks 10 and 11. The current employed should have a value sufficiently high to heat the tungsten powder-at least to its sintering -temperature'and preferably to a temperature of about 3000 C. The simultaneous applitungsten provides a solid anode substantial-.

lyintegral with the stem portion and sub stantially free from voids. When removed from the mold, the anode and stem, may be polished'and is then in condition for use.

If desired, the head portion 2010f the anode may be provided with a tungsten target 21 which is more dense than the remainder to the powdered tungsten through the movable carbon members 14 and 15. At a temperat'ure of about 3000 C. however, the carbon plungers'hayea tendency to buckle and break when pressure is applied to them. This difliculty is avoided by employing th 2 carbon members 14 and 15 merely to apply pressure to the tungsten powder and byapplying current through the sides of the mold, as indicated in F igs. 1 and 2 rather than through members 14: and 15.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. The method of making an electrode of refractory material which comprises surrounding one end of a metal stem with refractory material, and simultaneously applying heat and pressure to the refractory material.

2. The process of making an electrode of refractory material which comprises surrounding one end of a metal stem with refractory material, and simultaneously applying heat and pressure thereto in a confined space.

3. The process of making an electrode of refractory material which comprises surrounding one end of the metal stem with powdered refractory material, and simultaneously applying heat and pressure to the refractory material.

4. The process of making an electrode of refractory material which comprises surrounding one end of a metal stem with refractory material, heating the refractory material to a temperature at least as high as the sintering ten'iperature of the material, and simultaneously applying pressure thereto.

EMERY G. GILSON. 

